Conventionally, wiring harnesses are used for wiring in an automobile. Each of these wiring harnesses is made up of a bunch of electric wires including conductors that are coated with insulations, and includes a splice that is arranged to electrically connect the electric wires. The splice is formed by connecting the conductors by welding, soldering or crimping, which are exposed by peeling the insulations of the electric wires.
An exposed portion of the conductors that includes the splice is vulnerable to corrosion due to electrical leakage or contact of water if left as it is. For this reason, a sealing member that is made from a resin is formed on the splice in order to prevent electrical leakage and water immersion.
The conductors are bunched having narrow spaces left among them at a spot of their exposed portion excluding the splice. Thus, in forming the sealing member, the spaces also need to be filled with the resin in a convincing way.
The sealing member needs to be provided to the exposed portion of the conductors that includes the splice and also to an end portion of the bunch of the electric wires coated with the insulations that are adjacent to the exposed portion and the splice. The spaces are provided in a longitudinal direction among the electric wires, so that the sealing member needs to be provided so as to fill the spaces. If the spaces are not filled with the sealing member, water that comes in from the other end of the bunch of the electric wires could reach the splice through the spaces.
This kind of wiring harnesses are sometimes used for wiring in a site that is susceptible to water such as an engine room. In this case, the sealing members are required to be capable of filling these spaces among the electric wires in a convincing way.
PTL 1 discloses a technique for sealing a splice of a wiring harness with a thermal curing resin such as an epoxy resin. The thermal curing resin of PTL 1 is heated within a temperature span such that thermal cure develops relatively slowly, which can curb a sharp rise in viscosity caused by thermal cure. The technique disclosed in PTL 1 is capable of sufficiently filling spaces among bunched electric wires, and narrow spaces among exposed bunched conductors.
PTL 2 discloses a technique for sealing a splice of a wiring harness with a photocuring resin. In PTL 2, the splice of the wiring harness is immersed in a solution of the photocuring resin, is then picked up therefrom, and cured by irradiating the photocuring resin solution provided to the splice with light (ultraviolet light).